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Nanolenses: Beyond the limitстатья Научная хроника Электронная публикация
- Авторы: Lee J.Y., Hong B.H., Kim W.Y., Min S.K., Kim Y., Jouravlev M.V., Bose R., Kim K.S., I-C Hwang, Kaufman L.J., Wong C.W., Kim P., Kim K.S.
- Журнал: NPG Asia Materials
- Номер: 18
- Год издания: 2009
- DOI: 10.1038/asiamat.2009.18
- Аннотация: Spherical nanoscale lenses achieve near-field imaging beyond the diffraction limit. One of the fundamental constraints on the maximum resolution in geometrical optics is the diffraction limit. While technologies such as fluorescence microscopy can overcome this limit, conventional optical microscopy on the nanoscale is a challenge. Researchers from Pohang University of Science and Technology in Korea, with colleagues from Sungkyunkwan University in Korea and Columbia University in the USA1, have now fabricated nanolenses capable of optical resolution beyond these limitations. Miniature optical lenses are used for compact imaging and detection systems, and for focusing light onto tiny spots. However, these applications have been limited by diffraction to features larger than about half the wavelength of the light used. However, the situation changes when the lens size itself approaches the wavelength of light. “The resolution we achieved is much better than the diffraction limit, because the lens size is comparable to the wavelength, which leads to extremely short focal lengths,” says Kwang Kim, leader of the team. The researchers fabricated the tiny lenses using an organic molecule — calix[4]hydroquinone (CHQ) — that self-assembles into nanostructures such as nanotubes, nanospheres and nanolenses. Plano-spherical geometry was obtained by covering the structures with a thin CHQ film. Any material released from the nanostructures accumulated underneath the thin film, growing in a direction away from the substrate such that the plano-spherical lenses thus formed could be easily released. The nanolenses had extremely small focal lengths, which made it possible to clearly resolve stripe patterns with a line spacing of only 250 nm (Fig. 1). Features of this small size cannot be resolved by conventional optical microscopes. As the wavelength of light used for the optical microscopy was 472 nm, the imaging of features of smaller than 220 nm clearly demonstrates that the researchers had overcome the limit of classical optics, which is 260 nm for this experimental configuration. The nanolenses may be used in a number of applications ranging from optical lithography and imaging to memory devices, for which the technology could increase the storage density of optical disks. This new approach developed by Kim and his team marks the birth of a truly nanoscale optical microscope.
- Добавил в систему: Журавлев Mихаил В.